Conventional motor vehicles are provided with a powertrain comprising an internal combustion engine and a transmission for driving at least two wheels. The transmission comprises a gearbox mounted directly onto the engine, usually to the engine block. Vibrations generated by the engine or the transmission are dampened by passive or active damper means mounted between the powertrain and the vehicle frame, or a sub-frame attached to the vehicle frame. Such damper means can comprise elastic mounts or bushings.
US2007260377 discloses a conventional vehicle powertrain supporting apparatus where a transversely-mounted powertrain comprises an engine and a transmission arranged in a vehicle transvers direction. The engine and a transmission are connected to each other and are mounted on a vehicle body via a sub-frame and elastic dampers.
EP1650070A1 discloses an active engine mount for reducing vibration between a motor vehicle and a motor vehicle powertrain. The engine mount comprises at least a first damper means and a second damper means, located at either end of said power train and in respective vertical planes parallel to the crankshaft, and at least one controllable tie bar located in a plane substantially transverse to the crankshaft. The controllable tie bar is provided with means for adjusting the length of the damper in response to an output signal from an electronic control unit.
Powertrain suspensions of the above types will provide acceptable suppression of engine vibrations under many operating conditions. However, in some operating conditions sacrifices in terms of ride comfort must be accepted, as a consequence of torque oscillations in the powertrain or induced torque shock from one or more vehicle wheels transmitted via the transmission to the vehicle frame.
Hence there exists a need for an improved powertrain and powertrain mounts for reducing forces transferred to or from a drive unit located in a vehicle frame. Further, there exists a need for solving the combined problem of isolating and reducing both vibrations and excessive oscillations caused by engine motions or torque shock from the wheels.